Prismatic-glass globe or shade.



No. 805,742. v I PATENI'ED NOV. 28, 1905.

-0. A. MYGATT.

PRISMATIG GLASS GLOBE 0R SHADE.

APPLIOATIOH FILED JU-LY 13,1905.

[NVENTOR WITNESSES:

% WM Y 7 M Q 13mm B m Alforuey UNITED STATES PATENT OFFICE.

Specification of Letters Patent.-

Patented Nov. 28,1905.

Application filed July 13, 1905. Serial No. 269,646.

To all whom it may concern.-

Be it known that I, (his A. MYGATT, a citizen of the United States, residing at N.ew

York, in the county of New York and State of New York, have invented certain new and useful Im rovements in Prismatic-Glass Globes or hades, of which the following is aspecification, reference being had therein to e accompanying drawings. ThiSdTIVGIItiQIl relates to prismatic-glass light-controllin g and decorative globes and shades. The obi'ect of my present invention is to make a g'obe which shall have all the rich, sparkling, and decorative appearance of socalled bead-glass globes and yet have the.

efficiency of a scientifically-calculatedpris= matic-glass globe.

Prismatic globes as at present made have,

as a rule, their interior surface entirely cov-- ered with diffusing-prisms and their exterior surface covered with generally horizontal light-distributing prisms. The result of covering the interior inner surface with vertical or radial diffusing-prisms and the outer surface with horizontally-circumferential distributing-prisms is to give a globe having a nearly uniformly illuminated a pearance.

While in most cases of lighting t is evenlyilluminated appearance is soft on the eyesight and agreeable to most people, yet there are a great many cases where the lack of sparkle caused by the even diffusing and distributing of the light is objectionable.

. Bead-glass globes as now made and sold in large quantities are composed of cut-glass beads of different sizes, Wired through their center, and then wir'ed over a clear transparent globe in lines close together. globes are very expensive. They have a decorative appearance, however, and have therefore come into frequent use, notwithstanding their hi h expense, owing to the fact that they loo rich and there is a sort of fpalrkle about them which prism-glass globes Notwithstandin their rich and sparkling appearance and t eir great expense beadg ass globes absorb probably more light than any sort of glass lobe in the market. Tests made on such glass globes show that the waste of light is generally over fifty per cent. and frequently as large as eighty per cent.

Not only are bead-glass globes the worst glass portions.

Such glassabsorbers of light and are expensive, but they are the hardest to clean of any globes on the market.

My present invention is intended to produce a glass globe which shall be much. more economical in price than the bead-glass globe and which will be equallysparkling and rich in appearance, but give practically twice the light return, owin to the fact that in m globeall the sur aces can be calculate whereas in the bead-glass globe no surfaces whatever are calculated, they being composed but of glass beads of various sizes and outlines Wired'togeth'er. 5

The cause of ordinary prism-glass lobes being somewhat too evenly illuminate ,and therefore somewhat too monotonous as re gards sparkle, is owing to the whole interior and exterior'surfaoes being covered with diffusing-prisms and light-distributing prisms, so there is no chance'for the direct light from the lamp within to strike the eye.

What gives the bead-glass globe its rich effect is the factthat between the beads are clear spaces through which the incandescent filament of the lamp or source of light within reaches the eye direct without being diffused or dispersed by any intermediate surface.

This effect Iobtain by making the prisms of glass globes in the following way: I cover the inside of my globe with lunes ofone or more vertical prisms alternating with smooth I cover theout'side of my globe with zones of one or more horizontal diffusing or distributing prisms alternating with smooth glass portions.

Figure 1 is a partial section and'parti al elevation of a globe made according to my present invention. Fig. 2 is a horizontal central section of the same looking upward.

The body Aof the globe or shade is in this case shown as nearly s herical but any approved form may be a opted. The globe is shown in Fig. 1 1n the position it usually occupies when inelosing an incandescent electric lamp.

Around the outside of the globe are zones composed of light distributing prisms- B. These are prisms which permit most of the light-rays to pass through the glass, but serve to direct 'the rays. The zones are shown as composed of three prisms; but any number of prisms ma be grouped. I Between the zones of prisms there are plain or smooth zones C,

' to follow lunar lines on the globe.

through the surface of which the li ht-rays are transmitted without substantia deflection.

Inside the globe there areribs D, arranged These ribs serve to diffuse the light-ra s which reach them, but offer no substantia obstruction to their passage. The lunes are shown as com osed of threeribs; but other number might e used. Between the ribs D there are smooth or plain lunar spaces E, by which the li ht-rays are transmitted and not diverted. T e ribs show through the glass, giving a checkered or plaid appearance. r 5 places the light-rays wi lbe diffused by the internal ribs and distributed or directed by the external prisms in passing out of the lobe. At other places the rays wil be diffuse but not directed, in assin out of the smooth glass. At other p aces t e ra s smooth spaces, as at F l without being diverted andwill have brilliance and sparkle similar to some rays from beaded globes.

A study'of the drawings will show that the vertical smoothglass portions of the inside i and the horizontal smooth glass ortions on the outside where they cross see other become little squares or "windows through which the direct rays of a light within can reach the eye. It is this that gives beadglass its rich sparkling appearance, and by At certain.

will pass out ofthis means I make in a generally one-piece glass globe (though not necessarily one iece) an article which is far cheaper than .the eadlass globe, more than twice as eflicient in ight return, and its equal in richness and s arkle, owing to the numerous windows or clear glass spaces which occur at regular intervals over the surface of the globe.

What I claim is 1 1. A shade of transparent glass having on its inner surface diffusing-ribs with intermediate plain surfaces, and on its outer surfaces distributing prisms with interposed plain surfaces. 4 5

2. A shade of trans arent glass having luneslcomposed of a p uralityof diffusing; ribs, and plain surfaces between the lunes, and having externally light distributing prisms.

3. A shade of transparent glass havin lunes com osed of light-distributing ribs an interpose lunes of plain glass, and'havin external zones composed of a plurality o light-distributing prisms, and interposed 55 zones with plain surfaces.

In testimony whereof I affix my signature in presence of two witnesses.

orrs A. Mrea'r'r. 7

Witnesses:

H. E. NAso ROBERT KELLY, Jr. 

